Logon Screen Primary Monitor Panel
Available in: Actual Window Manager, Actual Multiple Monitors.
The Primary Monitor panel allows to change a background picture on the primary monitor of Logon Screen.
In the Background Settings group of controls you can specify:
System-managed picture radio button - select this option to keep the current picture assigned by the system. Click the related Settings... button to change a picture on the primary monitor of Lock Screen via system dialog (available since Windows 8);
Custom picture radio button - select this option to specify a custom picture. In the related group of controls you can specify a picture file, wallpaper position and background color.